If he is applying to highly selective schools, they will look at the rigor of the courses he has taken. If he does the Calc BC and then the honors math, that would be the most challenging track offered in the school. So there’s that. Is he in sports or something else that takes a lot of time? What are the other AP classes? One out-of-the box sequence would be to take AP Stats junior year and Calc BC senior year. This gives him the cachet of Calc BC and he still has time for the other AP classes his junior year. May want to talk to counselor about that.